Air injector for water well pressure systems



June 212, in# H. BIRDSALL am: mummia von WATER WELL sYsTEMs termed sept.2L, am

3,190,223 AIR INIECTOR FORWATER WELL Y PRESSURE SYSTEMS Dale H.Birdsall, 2830 Reed Ave., Livermore, Calif. Filed Sept. 21, 1962, Ser.No. 225,338

6 Claims. (Cl. 103'-6) The present invention relatesin general to adevice for recharging the air volume in a water well pressure system,and in particular to a device Vfor injecting air into, andthus'maintaining sufficient air volume in, a pressure tank of the typewhich depends upon a cushion of air for proper operation. Y

In domestic water systems, Water is pumped into a pressure tank at apoint near the bottom thereof. As the Water rises, the air already Vinthe tank is compressed againstV the upper end of the tank.V The systemis provided with a means for automatically stopping the water pump atsuch time as the pressure of the compressed air reaches a 4preset value.Therair thus compressed provides a cushion which will deliver, underpresure, a substantial part of the water in the tank (with anaccompanying drop in pressure), before the `pumpresupplies the tank withwater.

An inherent problem of such water systems is that the pressure tanktends to lose part of such cushion of air (e.g. due to absorption by thefresh water, leaks, etc.) after a period yof time. The reduction of laircushion volume causes the pumping on time to become shorter, and resultsin less water being pumped into the tank during each part of the oncycle. V.The air cushion can ,become so small in volume that the pumpingoperation resolves into a continuous start and stop operation of thepump.

There are several devices of varying configurations and theories ofoperation for solving the problem of air cushion loss in commercial useat the present time. In general, however, such devices comprise acomplicated maze of inter-coupled `components which are expensive toinstall and which are particularly diicult, time consuming andcumbersome to service. A prior art device of simple construction isinuse at the present time, but is extremely diicult to service. Suchdevice utilizes two orifices, which are inserted in Ithe water supplypipe of a watersystem to drain a section of the pipe and replace thewater with air during the off cycle of the pump. Since the orifices arelocated below the well cap the entire United States Patent O F. ICC

Therefore, it is an object of the present invention to provide a meansfor periodically recharging the air volume l installation fthereof.

supply pipe and attached pump must be raised sufficiently to permitservicing. This Yis a difiicult and time consuming operating, requiringheavy equipment and necessitating disassembly of portions of the Watersupply pipe. lIn this prior :art device it is furthermore extremelydiiiicult to alter the amount of air introduced to the pressure tankduring each cycle. Since most air recharging devices require periodiccleaning and/or servicing, it is particularly advantageous and`desirable toreplace the abovementioned complicated prior art devices (orthose devices which are diiiicult to service) with an inexpensive aircharging device of simple construction, which any layman can install andperiodically service with a minimum of labor, effort and expense..

The present invention solves not only the old problem of recharging theair cushion (volume) in a water well pressure system tank, but does soin an exceedingly simple and straight-forward manner. Intheory, meansare provided to siphon a volume of Water from the upper end of the watersupply pipe of a Water well system, and to replace such volume with aquantity of air. Upon operation of the pump the quantity of air isprevented from escaping to the atmosphere and is delivered along withthe water being pumped, to the pressure tank thereby replenishing anylosses in the air cushion volume therein.

It is a furtherobject ofthe present invention to provide a means forsiphoning a predetermined volume of water. from a water pressure system,and replacing such` volume of Water with air, which air is thendelivered to the pressure tank. l' 7 Y i It is yet a further object ofthe present invention to provide a pressure tank air charging devicewhich can be serviced without necessitating the removal of thenwate-rwell supply pipe from within the well casing.

Y It is still another object of the present invention toV provide anaircharging device which is unaffected -by temperature changes o r variouswater conditions,

Further objects and advantages will be apparent inthe followingdescription and claims considered together with the accompanyingdrawing, in which:

FIGURE 1 is a cross-sectional view'of the present invention as installedin a submersible pump water pressure system during, the oli V cyclethereof.

' FIGURE 2 is a cross-sectional viewof a portion of the inventionapparatus showing a modication thereof.

Referring to the drawing, a submersible pump 10'is connected to thebot-tom end of .a water supply pipe 12, which pipe extends from groundlevel to near bottom of a water well 14, within a well casing 16. Casing16 is provided with a casing cover 18 at its upper end. The

24. A pressure tank pipe 26 is connected to the swingV check valve 24,and provides Ymeans for delivering waterfrom submersible pump10,',through pipe 12 andV swingv check valve 24,to a pressure tank 27.

A The remaining outlet of pipe T 20 has threaded thereto.

a connecting nipple 28, which has in turn a capV 30 threaded thereon. Acheck (tair lsnifter) valve- 32 is secured to a hole through the cap 30by means of a suitable connection, such as -pipe.34. A breather vent 36is provided on the check .valve 32; the combination of valve 32, pipe 34and vent 36, operating to introduce air into an upper volume 38 of theWater supply pipe 12, as further described infra. The action of checkvalve 32 Yis to pass air downwardly into the water supply pipe 412 whilepreventing the passage of water from the system water line to theatmosphere. Y

. One end 40a of a siphon tube 40 (which preferably may comprise alength of copper tubing bent in the gen-V eral shape of a U) is extendedthroughY a second hole in packing nut 44 are provided (in conjunctionwith a proper seal` seat in cap 30) to insure an easily demountable'air-1 tight connection between the tube 40 and the cap 30.

,'I'he other end 4Gb of Siphon tube 40 extends downwardly, preferablythrough a hole in the casing cover 18,V

to protrude into the annular volume between casing 16 than the oppositeend a thereof.

and supply pipe 12. A leakcheck valve 46 is attached to the end 4Gb ofsiphon tube 40, and is positioned lower Leak valve 46` can bersimply arestricted orifice of constant diameter V(i.e., canY be achieved bypinching the end 4Gb of tube 40),

ori can be a diierential ball check lvalve whose seal seatV is slightlydeformed to purposely` allow leakage of a small quantity of watervtherethrough when the pump isi operating and the diierential ball checkvalve is in the closed position. casing cover 18 to prevent entrance ofdirt, insects,y and the like between tuber40 and casing cover 18. l Theseal 48 doesnot have to be air-tight, and can be any type of nut, cover,or packing whichis readily demountable and which will prevent entranceof Vforeign matter, into the well 1,4. As shown in FIGURE' l, tube 40maybe con- A ,sanitaryf sealAS is provided onk While the invention hasbeen described herein with Y respect to several embodiments, itwi1lbeapparent'that numerous variations and modifications mayV be'madewithin the spirit and scope .of the invention, and thus it is notintended to limit the invention except by the 1 structed in three parts;ytwo straight lengths 'of' tubing and one pre-formed return bendattached thereto in airtightV relation, preferably by means lofcompression fittings of the type used in refrigeration systems. a .j

The swing check valve 24 is a standard check valve as utilized insubmersible water pressure systems. Upon operation of pump 10 valve24'opens to allow the passage of water therethrough into thepressuretank 27. When pump |10 Stops, the Vpressure within `the tank 27forcesa swing gate within valve 24 against a seat thereinto thus isolatepipe 26 'and the pressure tank 27 from the rest of `the system- Inoperation of a pressure system inaccordance `with the conceptof thepresentk invention, when submersible pump' 10 starts, water flowstherefrom up supplypipe 12, through the, gate 50 in valve24 (asshown inVphantom i line in FIGURE l) through pipe 26 and into the pres,-

sure tank 27. Simultaneously, water is forced into the end 40a of Siphontube 40Jand the tube 40 is illed. Dur` ing operation of the pump (duringthe on cycle), a

small (and negligible) amount of water is forced through tube 40Y andthe leak check valve 46, and is returned toY the well y14 down theannular region between casing n 16 and supply pipe 12. During the -oncycle, the check valve 32 is closed by water pressurefthereag-ainst topre- Vent water from passing therethrough. When the pump 10 stops, thegate 50 of lvalve 24`closes due to vback- `mersi'ble pump to trap termsof the following claims. 4

VWhat is claimed is: Y l i A pressure tank air chargingdevice for useina water well pumping system including an air-tight pressure tank, asubmersible pump, a water supply pipe extending frontV said pump to saidpressure tank and a'water check valve Vdisposed in saidsupply pipe inthe region Ithereof near said pressure tank, said device comprising aSiphon tube having one end extending downwardly a substantial kdis-vtance through an upper portion of said supply pipe and in sealedrelationship therewith, said Siphon tube and supply pipe dening anannular volume therebetween, air( valve means connected -to saidupperportiony of supply. pipe in communication with said volume, said Aairvalve being adapted to open and introduce air into thepipe at such timeas said pump is inoperative, said siphon tube to Siphon a quantity ofwater from said supply pipe upon introduction of air `vthrough said airvalve. means, such quantity/'being commensurate to said volume therein`and4 determined by theextent of said siphon tube end therein, said airvalve means to close upon operationofl said sublthe air introduced to,said supply` plpe- Y 2. A pressure tank air charging device for use in awater well pressure system including a water supply pipe, a wellpressure from the tank 2.7, and the check valve 32 opens due tothe lackoffwater vpressure thereagainst@y Thus Siphon tube 40 continues itsSiphon action (sincethe upper end of pipe'12 is open to atmosphericpressure) and water is passed therethrough by way of leak valve 46during the pump oiY cycle. The rate of water leakage (during Vthe pumpon cycle) or of water siphoned (during the pump oft cycle) is regulatedby the size of the `orice Vof leak valve 46. The siphon action continuesuntil the water level .within pipe 12 reaches'the bottom of end 40a `ofthe Siphon tube l40,V at which pointV the siphon action ceases.` Asmentioned supra, the siphon action is generated by allowing'ar atatmosphericpres-V sure to enter pipe 12 through the check valve 32,whereby the volume of water siphoned through tube 40 is replaced by alike volume of air (volume'38herein).

Upon subsequent operation of pump 1l),A check valve 32 is closed bythewater pressureand the slugl of air entrapped in volume 38 is forcedthrough swing check valve 24 and into the pressure tank 27 alongwithnthe water pumped Vfrom the well 14. `Suchslug of air is forcedlinto'` the pressure tank each time the pump goes through a pumping on,oiTcycle y It may Vbe seen-from FIGUREY 1 that the size of the' ,volume38 (ie, the size of therslug of air) can be Varied simply by increasingVor decreasing the distance that end 40a of tube `40 extends into thepipe 12. VHowever it is to be understood that end 40a of tube/40 may beextended into the pipe4 12Vwith no regards as to the extent of volume38, and end 40b instead may beextended a predetermined distancedownwardly along pipe 12, as indicated in FIG- URE 2 by numeral 40e.Thus, at such time as the water casing, a pump, and a swing check valve,said supply pipe and casing defining therebetween an annular region,said device comprising a pipe,V T having one ofV `its outlets coupledtothe upper portion of said supply 'pipe and a-r second of its outletscoupled to said swing check valve; a Siphon tube having one endthereofdisposed in -Vairf tightrrelation through la third outlet of saidpipe .T andi.` into said supply pipe; the otherend of said tubeextending in-to the annular region between said supply pipe and the..casing of said water well; and a check valve coupledinl 1 air-tightrelation to saidupper portion-of saidfsupplypipey and adapted tointroduce Vair at atmospheric pressure into r the supply pipe at such.time as said pump is turned olf.`

3. A pressure tank air charging device foruse in a pres-Y sure systemhaving a submersible'pump connected Vt0 a` waterfsupply pipe comprisinga Siphon tube having'a first Y and a second end, said first`endextending into an upper portion of said supply pipe a substanti-aldistance, said Y w second end extending upwardly fromY said supply'pipeto terminate at a position lower than that of said iirst end,1V saidsecond end having a water restrictingrorifice securedy thereto, a checkvalve coupled Vto said upper portion of said supply pipe to introduceairat atmospheric pressure to said supply pipe at such time as said pumpis turned olf to cause said Siphon tube to Siphon water from said supplypipe and replace same with air,V y A' 4. A pressure` system airchargingdvevice forv use in a` submersible pump water pressure systemhaving casing, a

` water supply pipe, a pump, and a swing Yclie'ckvalv'e,

wherein said casing and kpipe denne therebetween an-an,

nular region, said device comprising a pipe T having. one outletthreaded to said supply pipe `and a second outlet threaded to said swingcheck valveya nipple demou'nt?.VV ably sealed to a thirdoutletfofsaid-pipe T; a cap demountably sealed to said nipple; a Siphontube having. one end thereof disposed in air-tight relation throughSaid.

cap and extending a predetermined distance through said T and into aportion of said supply pipe; a leak Valve secured to the other end ofsaid siphon tube; wherein said other endof the siphon Vtube is extendedinto the annular region between said supply pipe and Vsaid casingV to aposition lower than the end which is in the supply pipe; and a checkvalve coupled to Vsaid cap and adapted to open when said pump isinoperative to introduce air into said supply pipe, said check valve toclose upon operation of said pump to trap said `air within said supplypipe and deliver same to said pressure tank.

5. A pressure tank air charging device for use with a submersible pumpwater pressure system having a water t supply pipe extending from thesubmersed pump to the pressure tank and including a water check valvedisposed in-line Within said supply pipe, said device comprising,r aSiphon tube having an end extending a substantial distance into an upperportion of said supply pipe in sealed Y volume within said upperportion'of the'supply pipe,

air valve means connected to theY upper portion of said water supplypipe in communication with said substantial volume therein and adaptedto introduce air to said substantial volume at such time as said pump isinoperative, said siphon tube to provide a siphoning action for removingthe water contained in said substantial volume within said supply pipeupon introduction of air through said air valve means, said air valvemeans being adapted to close upon operation of said pump to trap in saidpipe the air introduced therein.

6. A pressure tank air charging device for use in a pressure systemhaving a submersible pump connected to a water supply pipe comprising aySiphon tube having a rst and a second end, said irst end extending intoan upper portion of said supply pipe a substantial distance, said secondend of said Siphon tubeV extending downwardly along saidl supply pipe asubstantial distance to terminate at a'position higher than thetermination of said iirst end, said second end having a waterrestricting orifice secured thereto, a check valve coupled to said upperportion of said supply pipe to introduce air at atmospheric pressure tosaid supply pipe at such time as said pump is turned off to cause saidSiphon tube to Siphon water from said supply pipe and replace same withair.

References Cited by the Examiner UNITED STATES PATENTS 1,625,892 4/ 27Hollander n 103-6 2,3 87,941 10/45 lPatterson V10S-6 2,787,220 4/57Patterson et al 103-6 2,847,939 8/58 Tubbs 103-6 2,851,951 9/58 Deters103-6 3,GO2,460 10/61 Ward 103---6Y FOREIGN PATENTS 765,445 3/ 34France.

LAURENCE V. EFNER, Primary Examiner.

1. A PRESSURE TANK AIR CHARGING DEVICE FOR USE IN A WATER WELL PUMPINGSYSTEM INCLUDING AN AIR-TIGHT PRESSURE TANK, A SUBMERSIBLE PUMP, A WATERSUPPLY PIPE EXTENDING FROM SAID PUMP TO SAID PRESSURE TANK AND A WATERCHECK VALVE DISPOSED IN SAID SUPPLY PIPE IN THE REGION THEREOF NEAR SAIDPRESSURE TANK, SAID DEVICE COMPRISING A SIPHON TUBE HAVING ONE ENDEXTENDING DOWNWARDLY A SUBSTANTIAL DISTANCE THROUGH AN UPPER PORTION OFSAID SUPPLY PIPE AND IN SEALED RELATIONSHIP THEREWITH, SAID SIPHON TUBEAND SUPPLY PIPE DEFINING AN ANNULAR VOLUME THEREBETWEEN, AIR VALVE MEANSCONNECTED TO SAID UPPER PORTION OF SUPPLY PIPE IN COMMUNICATION WITHSAID VOLUME, SAID AIR VALVE BEING ADAPTED TO OPEN AND INTRODUCE AIR INTOTHE PIPE AT SUCH TIME AS SAID PUMP IS INOPERATIVE, SAID SIPHON TUBE TOSIPHON A QUANTITY OF WATER FROM SAID SUPPLY PIPE UPON INTRODUCTION OFAIR THROUGH SAID AIR VALVE MEANS, SUCH QUANTITY BEING COMMENSURATE TOSAID VOLUME THEREIN AND DETERMINED BY THE EXTENT OF SAID SIPHON TUBE ENDTHEREIN, SAID AIR VALVE MEANS TO CLOSE UPON OPERATION OF SAIDSUBMERSIBLE PUMP TO TRAP THE AIR INTRODUCED TO SAID SUPPLY PIPE.